A great many viral, bacterial and fungal pathogens continue to be a threat to human health and a burden on health services1. Of particular concern are the influenza viruses and most notably the emergence of highly pathogenic H5N1 viruses and recent introductions of H7N9 viruses from avian sources'. These viruses exhibit the potential to acquire human transmissibility and thus represent an increased health threat3-5.
While vaccines remain a cornerstone of prevention, significant time is required to develop effective vaccines against these new pathogens. Antimicrobial drugs (including anti-virals particularly the influenza virus neuraminidase inhibitors and antibiotics), are available but their effectiveness can be compromised by the pathogen's ability to mutate and become drug resistant6,7. There is clearly a need for new therapeutic approaches.
A poster entitled “Engineering Multivalent Sialic Acid Recognition using the CBM40 module from Vibrio cholerae Sialidase” (published 17 May 2008) describes the development of reagents with increased affinity for sialic acid through multivalency. However, the poster does not disclose that such reagents have any application as immunomodulatory compounds useful in the treatment of diseases and/or conditions caused by pathogens.
US20020054880 (to Amstrong et al) describes peptides capable of binding terminally linked α-sialic acid(2→6)βGal- and/or α-sialic acid(2→3)βGal-groups and theft use in methods of inhibiting immune responses or cellular interactions in mammals. There is no disclosure of the immunostimulatory effect of sialic acid binding molecules.